package 二叉树;

public class lowestCommonAncestor {
    public TreeNode lowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q) {

        if(root==p || root==q || root==null){
            return root;
        }
        TreeNode left = lowestCommonAncestor(root.left, p, q);
        TreeNode right=lowestCommonAncestor(root.right,p,q);
        if(left!=null &&right!=null){
            return root;
        } else if(left!=null){
            return left;
        } else if(right!=null){
            return right;
        } else {
            return null;
        }
    }
}
